The invention relates to a path measuring apparatus comprising at least a first measuring path and a second measuring path, these measuring paths each having an extension in a longitudinal direction and being oriented parallel to one another in at least a measuring range, and comprising at least one position indicator which couples to the measuring paths in a non-contact manner.
EP 1 306 650 A1 discloses a transducer apparatus for detecting the path of a position indicator, said transducer apparatus comprising a measuring probe extending in a longitudinal direction, the position indicator coupling to the measuring probe in a non-contact manner.
If a plurality (at least two) measuring paths, i.e. at least two measuring probes, are provided, redundant path measurement or position detection can be achieved. A corresponding path measuring apparatus can be advantageously used for example in applications that are relevant to safety.
DE 10 2004 062 968 A1 discloses a path measuring apparatus comprising a housing in the form of an inherently stable hollow profile that is circumferentially closed and is sealable at an end face thereof and has a contour which is constant in cross-section; a waveguide unit located inside the profile, wherein the waveguide of the waveguide unit extends in a longitudinal direction of the profile; evaluation electronics; and, as a position indicator, a magnet movable in a longitudinal direction along the profile on the outside thereof. The profile has a stepless inner contour along the entire length thereof, and at least one insert having an inner contour is arranged so as to be rotationally fixed in a rotation direction about the longitudinal axis, said inner contour also having inner corners, outer corners and/or steps as desired.
US 2001/0017539 A1 discloses a modular waveguide assembly.
CN 101788259 discloses a magnetostrictive displacement sensor comprising two sets of signal generating devices. Each set comprises a waveguide wire.
DE 197 53 805 A1 discloses a support for waveguides which serve to conduct mechanical waves, wherein the support has a high proportion of gas and a low proportion of solid material.
U.S. Pat. No. 4,121,155 discloses a position determination system.